Howard Hughes takes on the challenge to build an enormous flying boat capable of airlifting 750 troops and war materiel as heavy as tanks across the Atlantic Ocean in support of the Allied ... See full summary »

In "Thaddeus and Thor", Phineas and Ferb compete with two visiting brothers to build the best treehouse. In "De Plane! De Plane!", the stepbrothers set out to build a plane like what Howard Hughes had built, using papier-mâché.